Zhang Ming-Xing, Zhang Jing, Yin Jun, Hartl František, Liu Sheng Hua
Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China.
Dalton Trans. 2018 May 1;47(17):6112-6123. doi: 10.1039/c8dt00584b.
Two related three-membered series of nonlinear aminophenylferrocene and diphenylaminoferrocene complexes were prepared and characterized by 1H and 13C NMR spectroscopy. The first series consists of 4-(diphenylamino)phenylferrocene (TPA-Fc, 1a), its dimethoxy-substituted tetraphenylphenylenediamine derivative (M2TPPD-Fc, 1c), and the triphenylamine-bridged bis(ferrocenyl) complex (Fc-TPA-Fc, 1b). The second series involves bis(4-methoxyphenyl)aminoferrocene (M2DPA-Fc, 1d), 4-methoxyphenylaminoferrocene (MPA-Fc) with N-phenyl-appended terminal TPA (1e), and the corresponding bis(MPA-Fc) complex with bridging TPA (1f). The structure of complex 1d was further confirmed by single crystal X-ray diffraction. Combined investigations, based on anodic voltammetry, UV-vis-NIR spectroelectrochemistry and density functional theory (DFT) calculations, were conducted to illustrate the influence of the integration of multiple redox-active components on the sequential oxidation of these complexes. The first anodic steps in 1a-1f are localized preferentially on the ferrocenyl units, followed by oxidation of the TPA or TPPD moieties (absent in 1d). Irreversible oxidation of the ferrocene-appended strong donor DPA/MPA units in 1d-1f terminates the anodic series. The one-electron oxidation of the triphenylamine-bridged diferrocenyl (1b) and bis(phenylaminoferrocenyl) (1f) complexes triggers their facile redox disproportionation to dicationic bis(ferrocenium) products.
制备了两个相关的由非线性氨基苯基二茂铁和二苯基氨基二茂铁络合物组成的三元系列，并通过¹H和¹³C核磁共振光谱对其进行了表征。第一个系列由4-（二苯基氨基）苯基二茂铁（TPA-Fc，1a）、其二甲氧基取代的四苯基苯二胺衍生物（M2TPPD-Fc，1c）以及三苯胺桥连的双（二茂铁基）络合物（Fc-TPA-Fc，1b）组成。第二个系列包括双（4-甲氧基苯基）氨基二茂铁（M2DPA-Fc，1d）、带有N-苯基末端TPA的4-甲氧基苯基氨基二茂铁（MPA-Fc）（1e）以及带有桥连TPA的相应双（MPA-Fc）络合物（1f）。通过单晶X射线衍射进一步证实了络合物1d的结构。基于阳极伏安法、紫外-可见-近红外光谱电化学和密度泛函理论（DFT）计算进行了综合研究，以阐明多个氧化还原活性成分的整合对这些络合物顺序氧化的影响。1a-1f中的第一个阳极步骤优先发生在二茂铁基单元上，随后是TPA或TPPD部分的氧化（1d中不存在）。1d-1f中二茂铁连接的强供体DPA/MPA单元的不可逆氧化终止了阳极系列。三苯胺桥连的双二茂铁基（1b）和双（苯基氨基二茂铁基）（1f）络合物的单电子氧化引发了它们向二价双（二茂铁鎓）产物的 facile 氧化还原歧化反应。
